1. Field of the Invention
This invention relates to a liquid unsaturated resin composition. More particularly, the invention relates to said resin composition which is used for coating material and forms an excellent coating film having superior water resistance, chemical resistance, solvent resistance and so forth. Furthermore, the present invention relates to said liquid unsaturated resin composition for coating material which contains little easily volatilizable component thus forming an excellent finished surface and causing no air pollution.
2. Description of Prior Art
In the conventional art, with respect to coating material, almost all sorts of resins such as polyesters, acrylic resins, epoxy resins and urethane resins are employed as the vehicles for electron beam-, ultraviolet ray- or catalyst-curable coating materials, the reactive unsaturated groups of which are introduced to the molecules of said resins through a variety of methods. They are, however, used by dilution with monovinyl monomer or several solvents. When the monovinyl monomer is used, the coating composition as formed is cured as it is, while in case solvents are used, the coating composition may be cured after setting or evaporation of the solvents by heat. Further, for convenience of the coating work, the coating compositions are usually diluted to 30 - 60% in resin content. In such circumstances, most of the monovinyl monomer evaporates during the coating step and curing step as it has a high vapor pressure, while in the use of solvent-type composition, the solvents should be forcibly evaporated. Nuisances to workers or others by bad odors and air pollution occur around the coating works, and, therefore the coating lines should be installed in a closed system. In addition, it is poor economy to exhaust the evaporated vinyl monomer, and it is impossible to completely eliminate the solvents from the waste gas.
In view of the above facts, the principal object of the present invention is to provide a novel and improved liquid resin composition for coating materials. A further object of the present invention is to provide a liquid unsaturated resin composition which forms an excellent coating film. A still further object of the present invention is to provide a liquid unsaturated resin composition which contains little easily volatilizable component to produce offensive odors and is cured by the application of electron beam or ultraviolet ray or catalytic reaction.